/*
 * Copyright (c) 2007-2012, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
package com.sun.org.apache.bcel.internal.generic;

/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2001 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Apache" and "Apache Software Foundation" and
 *    "Apache BCEL" must not be used to endorse or promote products
 *    derived from this software without prior written permission. For
 *    written permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache",
 *    "Apache BCEL", nor may "Apache" appear in their name, without
 *    prior written permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */
import com.sun.org.apache.bcel.internal.Constants;

/**
 * Instances of this class may be used, e.g., to generate typed
 * versions of instructions. Its main purpose is to be used as the
 * byte code generating backend of a compiler. You can subclass it to
 * add your own create methods.
 *
 * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
 * @see Constants
 */
public class InstructionFactory implements InstructionConstants, java.io.Serializable {
    protected ClassGen cg;
    protected ConstantPoolGen cp;

    public InstructionFactory(ClassGen cg, ConstantPoolGen cp) {
        this.cg = cg;
        this.cp = cp;
    }

    /** Initialize with ClassGen object
     */
    public InstructionFactory(ClassGen cg) {
        this(cg, cg.getConstantPool());
    }

    /** Initialize just with ConstantPoolGen object
     */
    public InstructionFactory(ConstantPoolGen cp) {
        this(null, cp);
    }

    /** Create an invoke instruction.
     *
     * @param class_name name of the called class
     * @param name name of the called method
     * @param ret_type return type of method
     * @param arg_types argument types of method
     * @param kind how to invoke, i.e., INVOKEINTERFACE, INVOKESTATIC, INVOKEVIRTUAL,
     * or INVOKESPECIAL
     * @see Constants
     */
    public InvokeInstruction createInvoke(String class_name, String name, Type ret_type, Type[] arg_types, short kind) {
        int index;
        int nargs = 0;
        String signature = Type.getMethodSignature(ret_type, arg_types);

        for (int i = 0; i < arg_types.length; i++)
            // Count size of arguments
            nargs += arg_types[i].getSize();

        if (kind == Constants.INVOKEINTERFACE)
            index = cp.addInterfaceMethodref(class_name, name, signature);
        else
            index = cp.addMethodref(class_name, name, signature);

        switch (kind) {
            case Constants.INVOKESPECIAL:
                return new INVOKESPECIAL(index);
            case Constants.INVOKEVIRTUAL:
                return new INVOKEVIRTUAL(index);
            case Constants.INVOKESTATIC:
                return new INVOKESTATIC(index);
            case Constants.INVOKEINTERFACE:
                return new INVOKEINTERFACE(index, nargs + 1);
            default:
                throw new RuntimeException("Oops: Unknown invoke kind:" + kind);
        }
    }

    /** Create a call to the most popular System.out.println() method.
     *
     * @param s the string to print
     */
    public InstructionList createPrintln(String s) {
        InstructionList il = new InstructionList();
        int out = cp.addFieldref("java.lang.System", "out", "Ljava/io/PrintStream;");
        int println = cp.addMethodref("java.io.PrintStream", "println", "(Ljava/lang/String;)V");

        il.append(new GETSTATIC(out));
        il.append(new PUSH(cp, s));
        il.append(new INVOKEVIRTUAL(println));

        return il;
    }

    /** Uses PUSH to push a constant value onto the stack.
     * @param value must be of type Number, Boolean, Character or String
     */
    public Instruction createConstant(Object value) {
        PUSH push;

        if (value instanceof Number)
            push = new PUSH(cp, (Number) value);
        else if (value instanceof String)
            push = new PUSH(cp, (String) value);
        else if (value instanceof Boolean)
            push = new PUSH(cp, (Boolean) value);
        else if (value instanceof Character)
            push = new PUSH(cp, (Character) value);
        else
            throw new ClassGenException("Illegal type: " + value.getClass());

        return push.getInstruction();
    }

    private static class MethodObject {
        Type[] arg_types;
        Type result_type;
        String[] arg_names;
        String class_name;
        String name;
        int access;

        MethodObject(String c, String n, Type r, Type[] a, int acc) {
            class_name = c;
            name = n;
            result_type = r;
            arg_types = a;
            access = acc;
        }
    }

    private InvokeInstruction createInvoke(MethodObject m, short kind) {
        return createInvoke(m.class_name, m.name, m.result_type, m.arg_types, kind);
    }

    private static MethodObject[] append_mos = { new MethodObject("java.lang.StringBuffer", "append", Type.STRINGBUFFER, new Type[] { Type.STRING }, Constants.ACC_PUBLIC), new MethodObject("java.lang.StringBuffer", "append", Type.STRINGBUFFER, new Type[] { Type.OBJECT }, Constants.ACC_PUBLIC), null, null, // indices 2, 3
    new MethodObject("java.lang.StringBuffer", "append", Type.STRINGBUFFER, new Type[] { Type.BOOLEAN }, Constants.ACC_PUBLIC), new MethodObject("java.lang.StringBuffer", "append", Type.STRINGBUFFER, new Type[] { Type.CHAR }, Constants.ACC_PUBLIC), new MethodObject("java.lang.StringBuffer", "append", Type.STRINGBUFFER, new Type[] { Type.FLOAT }, Constants.ACC_PUBLIC), new MethodObject("java.lang.StringBuffer", "append", Type.STRINGBUFFER, new Type[] { Type.DOUBLE }, Constants.ACC_PUBLIC), new MethodObject("java.lang.StringBuffer", "append", Type.STRINGBUFFER, new Type[] { Type.INT }, Constants.ACC_PUBLIC), new MethodObject("java.lang.StringBuffer", "append", Type.STRINGBUFFER, // No append(byte)
    new Type[] { Type.INT }, Constants.ACC_PUBLIC), new MethodObject("java.lang.StringBuffer", "append", Type.STRINGBUFFER, // No append(short)
    new Type[] { Type.INT }, Constants.ACC_PUBLIC), new MethodObject("java.lang.StringBuffer", "append", Type.STRINGBUFFER, new Type[] { Type.LONG }, Constants.ACC_PUBLIC) };

    private static final boolean isString(Type type) {
        return ((type instanceof ObjectType) && ((ObjectType) type).getClassName().equals("java.lang.String"));
    }

    public Instruction createAppend(Type type) {
        byte t = type.getType();

        if (isString(type))
            return createInvoke(append_mos[0], Constants.INVOKEVIRTUAL);

        switch (t) {
            case Constants.T_BOOLEAN:
            case Constants.T_CHAR:
            case Constants.T_FLOAT:
            case Constants.T_DOUBLE:
            case Constants.T_BYTE:
            case Constants.T_SHORT:
            case Constants.T_INT:
            case Constants.T_LONG:
                return createInvoke(append_mos[t], Constants.INVOKEVIRTUAL);
            case Constants.T_ARRAY:
            case Constants.T_OBJECT:
                return createInvoke(append_mos[1], Constants.INVOKEVIRTUAL);
            default:
                throw new RuntimeException("Oops: No append for this type? " + type);
        }
    }

    /** Create a field instruction.
     *
     * @param class_name name of the accessed class
     * @param name name of the referenced field
     * @param type  type of field
     * @param kind how to access, i.e., GETFIELD, PUTFIELD, GETSTATIC, PUTSTATIC
     * @see Constants
     */
    public FieldInstruction createFieldAccess(String class_name, String name, Type type, short kind) {
        int index;
        String signature = type.getSignature();

        index = cp.addFieldref(class_name, name, signature);

        switch (kind) {
            case Constants.GETFIELD:
                return new GETFIELD(index);
            case Constants.PUTFIELD:
                return new PUTFIELD(index);
            case Constants.GETSTATIC:
                return new GETSTATIC(index);
            case Constants.PUTSTATIC:
                return new PUTSTATIC(index);

            default:
                throw new RuntimeException("Oops: Unknown getfield kind:" + kind);
        }
    }

    /** Create reference to `this'
     */
    public static Instruction createThis() {
        return new ALOAD(0);
    }

    /** Create typed return
     */
    public static ReturnInstruction createReturn(Type type) {
        switch (type.getType()) {
            case Constants.T_ARRAY:
            case Constants.T_OBJECT:
                return ARETURN;
            case Constants.T_INT:
            case Constants.T_SHORT:
            case Constants.T_BOOLEAN:
            case Constants.T_CHAR:
            case Constants.T_BYTE:
                return IRETURN;
            case Constants.T_FLOAT:
                return FRETURN;
            case Constants.T_DOUBLE:
                return DRETURN;
            case Constants.T_LONG:
                return LRETURN;
            case Constants.T_VOID:
                return RETURN;

            default:
                throw new RuntimeException("Invalid type: " + type);
        }
    }

    private static final ArithmeticInstruction createBinaryIntOp(char first, String op) {
        switch (first) {
            case '-':
                return ISUB;
            case '+':
                return IADD;
            case '%':
                return IREM;
            case '*':
                return IMUL;
            case '/':
                return IDIV;
            case '&':
                return IAND;
            case '|':
                return IOR;
            case '^':
                return IXOR;
            case '<':
                return ISHL;
            case '>':
                return op.equals(">>>") ? (ArithmeticInstruction) IUSHR : (ArithmeticInstruction) ISHR;
            default:
                throw new RuntimeException("Invalid operand " + op);
        }
    }

    private static final ArithmeticInstruction createBinaryLongOp(char first, String op) {
        switch (first) {
            case '-':
                return LSUB;
            case '+':
                return LADD;
            case '%':
                return LREM;
            case '*':
                return LMUL;
            case '/':
                return LDIV;
            case '&':
                return LAND;
            case '|':
                return LOR;
            case '^':
                return LXOR;
            case '<':
                return LSHL;
            case '>':
                return op.equals(">>>") ? (ArithmeticInstruction) LUSHR : (ArithmeticInstruction) LSHR;
            default:
                throw new RuntimeException("Invalid operand " + op);
        }
    }

    private static final ArithmeticInstruction createBinaryFloatOp(char op) {
        switch (op) {
            case '-':
                return FSUB;
            case '+':
                return FADD;
            case '*':
                return FMUL;
            case '/':
                return FDIV;
            default:
                throw new RuntimeException("Invalid operand " + op);
        }
    }

    private static final ArithmeticInstruction createBinaryDoubleOp(char op) {
        switch (op) {
            case '-':
                return DSUB;
            case '+':
                return DADD;
            case '*':
                return DMUL;
            case '/':
                return DDIV;
            default:
                throw new RuntimeException("Invalid operand " + op);
        }
    }

    /**
     * Create binary operation for simple basic types, such as int and float.
     *
     * @param op operation, such as "+", "*", "<<", etc.
     */
    public static ArithmeticInstruction createBinaryOperation(String op, Type type) {
        char first = op.toCharArray()[0];

        switch (type.getType()) {
            case Constants.T_BYTE:
            case Constants.T_SHORT:
            case Constants.T_INT:
            case Constants.T_CHAR:
                return createBinaryIntOp(first, op);
            case Constants.T_LONG:
                return createBinaryLongOp(first, op);
            case Constants.T_FLOAT:
                return createBinaryFloatOp(first);
            case Constants.T_DOUBLE:
                return createBinaryDoubleOp(first);
            default:
                throw new RuntimeException("Invalid type " + type);
        }
    }

    /**
     * @param size size of operand, either 1 (int, e.g.) or 2 (double)
     */
    public static StackInstruction createPop(int size) {
        return (size == 2) ? (StackInstruction) POP2 : (StackInstruction) POP;
    }

    /**
     * @param size size of operand, either 1 (int, e.g.) or 2 (double)
     */
    public static StackInstruction createDup(int size) {
        return (size == 2) ? (StackInstruction) DUP2 : (StackInstruction) DUP;
    }

    /**
     * @param size size of operand, either 1 (int, e.g.) or 2 (double)
     */
    public static StackInstruction createDup_2(int size) {
        return (size == 2) ? (StackInstruction) DUP2_X2 : (StackInstruction) DUP_X2;
    }

    /**
     * @param size size of operand, either 1 (int, e.g.) or 2 (double)
     */
    public static StackInstruction createDup_1(int size) {
        return (size == 2) ? (StackInstruction) DUP2_X1 : (StackInstruction) DUP_X1;
    }

    /**
     * @param index index of local variable
     */
    public static LocalVariableInstruction createStore(Type type, int index) {
        switch (type.getType()) {
            case Constants.T_BOOLEAN:
            case Constants.T_CHAR:
            case Constants.T_BYTE:
            case Constants.T_SHORT:
            case Constants.T_INT:
                return new ISTORE(index);
            case Constants.T_FLOAT:
                return new FSTORE(index);
            case Constants.T_DOUBLE:
                return new DSTORE(index);
            case Constants.T_LONG:
                return new LSTORE(index);
            case Constants.T_ARRAY:
            case Constants.T_OBJECT:
                return new ASTORE(index);
            default:
                throw new RuntimeException("Invalid type " + type);
        }
    }

    /**
     * @param index index of local variable
     */
    public static LocalVariableInstruction createLoad(Type type, int index) {
        switch (type.getType()) {
            case Constants.T_BOOLEAN:
            case Constants.T_CHAR:
            case Constants.T_BYTE:
            case Constants.T_SHORT:
            case Constants.T_INT:
                return new ILOAD(index);
            case Constants.T_FLOAT:
                return new FLOAD(index);
            case Constants.T_DOUBLE:
                return new DLOAD(index);
            case Constants.T_LONG:
                return new LLOAD(index);
            case Constants.T_ARRAY:
            case Constants.T_OBJECT:
                return new ALOAD(index);
            default:
                throw new RuntimeException("Invalid type " + type);
        }
    }

    /**
     * @param type type of elements of array, i.e., array.getElementType()
     */
    public static ArrayInstruction createArrayLoad(Type type) {
        switch (type.getType()) {
            case Constants.T_BOOLEAN:
            case Constants.T_BYTE:
                return BALOAD;
            case Constants.T_CHAR:
                return CALOAD;
            case Constants.T_SHORT:
                return SALOAD;
            case Constants.T_INT:
                return IALOAD;
            case Constants.T_FLOAT:
                return FALOAD;
            case Constants.T_DOUBLE:
                return DALOAD;
            case Constants.T_LONG:
                return LALOAD;
            case Constants.T_ARRAY:
            case Constants.T_OBJECT:
                return AALOAD;
            default:
                throw new RuntimeException("Invalid type " + type);
        }
    }

    /**
     * @param type type of elements of array, i.e., array.getElementType()
     */
    public static ArrayInstruction createArrayStore(Type type) {
        switch (type.getType()) {
            case Constants.T_BOOLEAN:
            case Constants.T_BYTE:
                return BASTORE;
            case Constants.T_CHAR:
                return CASTORE;
            case Constants.T_SHORT:
                return SASTORE;
            case Constants.T_INT:
                return IASTORE;
            case Constants.T_FLOAT:
                return FASTORE;
            case Constants.T_DOUBLE:
                return DASTORE;
            case Constants.T_LONG:
                return LASTORE;
            case Constants.T_ARRAY:
            case Constants.T_OBJECT:
                return AASTORE;
            default:
                throw new RuntimeException("Invalid type " + type);
        }
    }

    /** Create conversion operation for two stack operands, this may be an I2C, instruction, e.g.,
     * if the operands are basic types and CHECKCAST if they are reference types.
     */
    public Instruction createCast(Type src_type, Type dest_type) {
        if ((src_type instanceof BasicType) && (dest_type instanceof BasicType)) {
            byte dest = dest_type.getType();
            byte src = src_type.getType();

            if (dest == Constants.T_LONG && (src == Constants.T_CHAR || src == Constants.T_BYTE || src == Constants.T_SHORT))
                src = Constants.T_INT;

            String[] short_names = { "C", "F", "D", "B", "S", "I", "L" };

            String name = "com.sun.org.apache.bcel.internal.generic." + short_names[src - Constants.T_CHAR] + "2" + short_names[dest - Constants.T_CHAR];

            Instruction i = null;
            try {
                i = (Instruction) java.lang.Class.forName(name).newInstance();
            } catch (Exception e) {
                throw new RuntimeException("Could not find instruction: " + name);
            }

            return i;
        } else if ((src_type instanceof ReferenceType) && (dest_type instanceof ReferenceType)) {
            if (dest_type instanceof ArrayType)
                return new CHECKCAST(cp.addArrayClass((ArrayType) dest_type));
            else
                return new CHECKCAST(cp.addClass(((ObjectType) dest_type).getClassName()));
        } else
            throw new RuntimeException("Can not cast " + src_type + " to " + dest_type);
    }

    public GETFIELD createGetField(String class_name, String name, Type t) {
        return new GETFIELD(cp.addFieldref(class_name, name, t.getSignature()));
    }

    public GETSTATIC createGetStatic(String class_name, String name, Type t) {
        return new GETSTATIC(cp.addFieldref(class_name, name, t.getSignature()));
    }

    public PUTFIELD createPutField(String class_name, String name, Type t) {
        return new PUTFIELD(cp.addFieldref(class_name, name, t.getSignature()));
    }

    public PUTSTATIC createPutStatic(String class_name, String name, Type t) {
        return new PUTSTATIC(cp.addFieldref(class_name, name, t.getSignature()));
    }

    public CHECKCAST createCheckCast(ReferenceType t) {
        if (t instanceof ArrayType)
            return new CHECKCAST(cp.addArrayClass((ArrayType) t));
        else
            return new CHECKCAST(cp.addClass((ObjectType) t));
    }

    public INSTANCEOF createInstanceOf(ReferenceType t) {
        if (t instanceof ArrayType)
            return new INSTANCEOF(cp.addArrayClass((ArrayType) t));
        else
            return new INSTANCEOF(cp.addClass((ObjectType) t));
    }

    public NEW createNew(ObjectType t) {
        return new NEW(cp.addClass(t));
    }

    public NEW createNew(String s) {
        return createNew(new ObjectType(s));
    }

    /** Create new array of given size and type.
     * @return an instruction that creates the corresponding array at runtime, i.e. is an AllocationInstruction
     */
    public Instruction createNewArray(Type t, short dim) {
        if (dim == 1) {
            if (t instanceof ObjectType)
                return new ANEWARRAY(cp.addClass((ObjectType) t));
            else if (t instanceof ArrayType)
                return new ANEWARRAY(cp.addArrayClass((ArrayType) t));
            else
                return new NEWARRAY(((BasicType) t).getType());
        } else {
            ArrayType at;

            if (t instanceof ArrayType)
                at = (ArrayType) t;
            else
                at = new ArrayType(t, dim);

            return new MULTIANEWARRAY(cp.addArrayClass(at), dim);
        }
    }

    /** Create "null" value for reference types, 0 for basic types like int
     */
    public static Instruction createNull(Type type) {
        switch (type.getType()) {
            case Constants.T_ARRAY:
            case Constants.T_OBJECT:
                return ACONST_NULL;
            case Constants.T_INT:
            case Constants.T_SHORT:
            case Constants.T_BOOLEAN:
            case Constants.T_CHAR:
            case Constants.T_BYTE:
                return ICONST_0;
            case Constants.T_FLOAT:
                return FCONST_0;
            case Constants.T_DOUBLE:
                return DCONST_0;
            case Constants.T_LONG:
                return LCONST_0;
            case Constants.T_VOID:
                return NOP;

            default:
                throw new RuntimeException("Invalid type: " + type);
        }
    }

    /** Create branch instruction by given opcode, except LOOKUPSWITCH and TABLESWITCH.
     * For those you should use the SWITCH compound instruction.
     */
    public static BranchInstruction createBranchInstruction(short opcode, InstructionHandle target) {
        switch (opcode) {
            case Constants.IFEQ:
                return new IFEQ(target);
            case Constants.IFNE:
                return new IFNE(target);
            case Constants.IFLT:
                return new IFLT(target);
            case Constants.IFGE:
                return new IFGE(target);
            case Constants.IFGT:
                return new IFGT(target);
            case Constants.IFLE:
                return new IFLE(target);
            case Constants.IF_ICMPEQ:
                return new IF_ICMPEQ(target);
            case Constants.IF_ICMPNE:
                return new IF_ICMPNE(target);
            case Constants.IF_ICMPLT:
                return new IF_ICMPLT(target);
            case Constants.IF_ICMPGE:
                return new IF_ICMPGE(target);
            case Constants.IF_ICMPGT:
                return new IF_ICMPGT(target);
            case Constants.IF_ICMPLE:
                return new IF_ICMPLE(target);
            case Constants.IF_ACMPEQ:
                return new IF_ACMPEQ(target);
            case Constants.IF_ACMPNE:
                return new IF_ACMPNE(target);
            case Constants.GOTO:
                return new GOTO(target);
            case Constants.JSR:
                return new JSR(target);
            case Constants.IFNULL:
                return new IFNULL(target);
            case Constants.IFNONNULL:
                return new IFNONNULL(target);
            case Constants.GOTO_W:
                return new GOTO_W(target);
            case Constants.JSR_W:
                return new JSR_W(target);
            default:
                throw new RuntimeException("Invalid opcode: " + opcode);
        }
    }

    public void setClassGen(ClassGen c) {
        cg = c;
    }

    public ClassGen getClassGen() {
        return cg;
    }

    public void setConstantPool(ConstantPoolGen c) {
        cp = c;
    }

    public ConstantPoolGen getConstantPool() {
        return cp;
    }
}
